Harlequin Truffle Roulade

Harlequin Truffle Roulade

If you've been reading this blog for very long, then you know I love a cake roll. I found this recipe in a secondhand baking textbook, and was instantly smitten. The alternating chocolate ganache and vanilla buttercream interior was so striking on the page, I had to try my hand at the technique.

Compared to the eye-catching interior, the outside of the cake seemed a little plain. That was easily remedied with a swirl of dark chocolate ganache buttercream on top and an assortment of truffles. You may also recall how much I lovebonbons on cake.

Below you'll find a pictoral of the Harlequin buttercream filling process. I think the finished cake looks quite daunting, but once you see how it's made, you may be inspired to try it! It's easier than it looks.

This last process shot is my favorite. I had anticipated having a real mess on my hands after rolling up the cake, but it was a relatively tidy affair. It's important that the buttercream isn't too lax in texture. It should have a little heft to it so it rolls up nice and clean.

One prerequisite for this recipe - you must like buttercream (no issues here!). This cake is rich, so a small slice goes a long way. The textbook suggests using slices of this cake to create a beautiful dessert tray. I can imagine slices fanned out on a fancy platter would be quite pretty.

In a saucepan, bring the cream to a simmer. Remove from
the heat and pour in the chopped chocolate. Whisk to combine. Transfer the
mixture to a shallow dish and transfer to the refrigerator. Stir the mixture
intermittently to speed cooling.

In a large bowl beat the butter until creamy. Add the
confectioners’ sugar and beat until light and fluffy, about 4 minutes. Beat in
the vanilla extract and pinch of salt.

Remove half of the frosting and place it in a piping bag
fitted with a 1/2-inch decorator tip (or no tip, and a 1/2-inch hole cut in the
end). Beat the cooled chocolate mixture and 2 tablespoons dark cocoa into the
remaining frosting. Transfer the chocolate frosting to a piping bag fitted with
1/2-inch decorator tip (or no tip, and a 1/2-inch hole cut as previously
mentioned). Set aside. Keep the bags at room temperature.

Sponge roll

1/2 cup egg yolks (about 7 yolks from large eggs)

3 tablespoons/ 1 1/2 ounces granulated sugar

1 tablespoon vegetable oil

1/3 cup/2 ounces cake flour, sifted

1/4 cup egg whites (about 2 egg whites from large eggs)

Confectioners’ sugar for dusting

Beat the egg yolks and sugar together in a standing mixer
on high speed until light in color, about 5-8 minutes. Gradually add in the
oil. You can tell the mixture is properly whipped when it has the appearance of
lemon pudding.

Gently fold in the cake flour using a large rubber
spatula. Set aside.

Beat the egg whites in a separate bowl until soft peaks
form. Gently fold the beaten egg whites into the yolk mixture.

Preheat the oven to 350°F. Grease a 10x 15-inch baking sheet with
vegetables shortening and line it with parchment paper (the greased surface
helps the paper to stick to the pan). Carefully spread the mixture in an even
layer over the parchment with an offset spatula.

Bake for 8 to 10 minutes, or until the cake just starts
to brown around the edges. The cake may look glossy and underdone in the
middle, but looks can be deceiving. Check the cake’s center by pressing your
finger on the cake. If it springs back, it’s done. Be careful not to over-bake
this cake, or it break into pieces as you try to roll it.

Let the cake cool slightly. Run a knife around the edge
of the pan and turn the cake onto a work surface dusted with powdered sugar
(put a piece of waxed paper down first and clean-up will be a snap). Peel off
the parchment paper. Trim the brown edges away from the cake. Let the cake cool
completely.

Pipe spaced lines of chocolate frosting across the length
of the cake. Leave just enough space to allow for same-sized lines of white
icing between the chocolate icing. Pipe the white frosting between the
chocolate rows, filling the gaps completely. You should have leftover chocolate
frosting, reserve it for later use. Gently begin to roll the cake, starting at
a long side, pushing it forward with your fingers. Roll the cake up completely
and wipe away any excess frosting that gets squished out during rolling. Place
the cake roll on a large sheet of waxed paper (or parchment) and roll the cake
up into the paper. Chill the cake in the freezer until firm.

Chocolate glaze
and topping

4 oz. chocolate, finely chopped

1/2 cup/120 g heavy cream

Assorted chocolate bonbons

Place heavy cream in a large microwaveable bowl. Heat in the microwave at 40 second intervals
until very hot but not boiling (you can do this on the stove top if you don’t
have a microwave). Stir in chopped chocolate.
Let stand for 3 minutes then begin gently stirring mixture. You can use a whisk, but do not whisk
vigorously as it will create air bubbles in the finished glaze.

Remove cake from freezer and place it on a grid baking
rack; place the rack on top of a large baking pan. Pour glaze over entire
surface, allowing the excess to drip into the pan. Let stand for 2 minutes, and
then transfer the cake to the freezer.

Transfer the remaining chocolate frosting to a piping bag
fitted with a large open star tip. Pipe an undulating line of frosting on top
of the cake. Garnish with chocolate bonbons. Cut the cake into pieces with a
warmed knife, cleaning between slices, while it is still cold. Let the slices
come to room temperature before serving.

I think I am running out of ways to express my awe for your creativity when it comes to desserts! Everything looks amazing and delicious! It's a great balance as we actually eat with our eyes before any of our other senses!

This looks amazing.. somehow all of your recipes look so perfect, I have to try them ALL!! I'm 14 and an avid baker. I just started a blog (attached to my name) and it would be amazing for you to check it out!